An “LED” driving circuit comprises an “LED” driving voltage generator which generates an “LED” driving voltage, a pulse width modulation (“PWM”) control unit which outputs a “PWM” signal having a predetermined duty ratio, and a main switching unit which controls the driving voltage applied to the “LEDs” in accordance with the “PWM” signal. Further, the “PWM” control unit comprises a controller including an error amplifier which detects an error between a reference voltage and a driving voltage and amplifies the detected error, an oscillator which outputs a pulse signal having a predetermined oscillation frequency, and a comparator which compares the pulse signal output from the oscillator with an output voltage from the error amplifier to generate a “PWM” signal; and a high frequency damper connected to the main switching unit to prevent malfunction of the controller due to noise. A backlight unit and liquid crystal display incorporate the “LED” driving circuit.